Measuring thiamine status in dried blood spots

Area of Science:

• Biochemistry
• Analytical Chemistry
• Clinical Diagnostics

Background:

• A need exists for reliable and robust thiamine assays with minimal sample requirements in clinical and research settings.
• Current methods may be limited by sample volume or complexity.

Purpose of the Study:

• To develop and validate a simple, robust assay for quantifying three key thiamine vitamers (Th, TMP, TDP) in dried blood spots (DBS).
• To assess the assay's accuracy, precision, linearity, recovery, and stability.
• To compare DBS assay results with traditional venous blood measurements.

Main Methods:

• Development and validation of a novel assay using a 6.35-mm DBS disc.
• Quantification of thiamine (Th), thiamine monophosphate (TMP), and thiamine diphosphate (TDP).
• Cross-comparison with venous whole blood and pre-spotted filter paper samples from 20 healthy participants.

Main Results:

• The assay demonstrated acceptable recovery (90%-114%) and high precision (CV < 4.3% for TDP, <10.0% for TMP, <12.6% for Th).
• Excellent linearity (R² > 0.99) and stability at -20°C for up to 42 days were achieved.
• Minimal bias was observed when comparing DBS results with venous blood methods; the assay showed high sensitivity to thiamine supplementation.

Conclusions:

• A clinically validated, simple, robust, accurate, and sensitive assay for thiamine status analysis in DBS has been developed.
• The assay is suitable for large-scale population studies, offering a practical solution for assessing thiamine levels.
• This method facilitates improved thiamine status monitoring in diverse settings.